We propose to investigate the physiologic and morphologic changes induced by alcohol in the developing heart. Fetal and neonatal morbidity and mortality have recently been recognized as a major consequence of alcohol consumption during pregnancy. Accordingly, we plan to study acute and chronic exposure to alcohol in the embryonic chick. Our examination will include analysis of the dose-response relationship with injection of known concentrations of alcohol at critical points in gestation. Evaluation of response will be done by direct examination of cardiac function by cinephotoanalysis and of associated morphologic change by light and electron microscopy. Effective delivered dose will be determined by gas chromatographic analysis of tissue homogenates of paired embryos sacrificed at times corresponding to function-morphology evaluation. We expect to show that alcohol induces cell injury and death which, in turn, impairs function, alters the resultant streaming of blood, and interferes with the ultimate anatomic development of the entire heart. We plan also to evaluate the possibility of repair by studying embryos at intervals of 24 and 48 hours after alcohol exposure, using cinephotoanalysis and light and electron microscopy. Accordingly, the research proposed cinephotoanalysis and light and electron microscopy. Accordingly, the research proposed in our animal model will help to clarify not only mechanisms of myocardial damage induced by alcohol, but also the etiology of potentially lethal congenital heart defects.